Miyamoto J
Environ Health Perspect. 1976 Apr;14:15-28. doi: 10.1289/ehp.761415.
Synthetic pyrethroidal compounds undergo biodegradation in mammals both oxidatively and hydrolytically, and depending on the type of compound, either of the pathways may predominate. Thus, (+) - or (+/-) -trans isomers of the chrysanthemumate ester of primary alcohols such as fenothrin, furamethrin, proparthrin, resmethrin, and tetramethrin (and possibly permethrin, too) are metabolized mainly through hydrolysis of the ester linkage, with subsequent oxidation and/or conjugation of the component alcohol and acid moieties. On the other hand, the corresponding (+)-cis enantiometers and chrysanthemumate of secondary alcohols like allethrin are resistant to hydrolytic attack, and biodegraded via oxidation at various sites of the molecule. These rapid metabolic degradations, together with the presumable incomplete absorption from the gastrointestinal tract, would generally contribute to the low acute toxicity of synthetic pyrethroids. These compounds are neither skin irritants nor skin sensitizers, and inhalation toxicity as well as dermal toxicity are fairly low. Neither is teratogenic in rats, mice, and/or rabbits or mutagenic on various bacterial strains. Subacute and chronic feeding of higher amounts of the compounds to rats invariably causes some histopathological changes in liver; however, these are neither indicative nor suggestive of tumorigenicity. Based on existing toxicological information, the present recommended use patterns might afford sufficient safety margin on human population. However, in extending usage to agricultural pest control, much more extensive investigations should be forthcoming from both chemical and biological aspects, since there is scant information on the fate of these pyrethroids in the environment. Also several of the compounds may be very toxic to certain kinds of fish and arthropods.
合成拟除虫菊酯类化合物在哺乳动物体内可通过氧化和水解两种方式进行生物降解，具体取决于化合物的类型，其中一种途径可能占主导地位。因此，诸如苯醚菊酯、氟胺氰菊酯、炔丙菊酯、苄呋菊酯和胺菊酯（可能还有氯菊酯）等伯醇菊酸酯的(+) - 或(+/-) -反式异构体主要通过酯键水解进行代谢，随后其醇和酸部分会发生氧化和/或结合。另一方面，诸如丙烯菊酯等仲醇的相应(+) -顺式对映体和菊酸酯对水解作用具有抗性，通过分子不同位点的氧化进行生物降解。这些快速的代谢降解，再加上胃肠道可能不完全吸收，通常会导致合成拟除虫菊酯的急性毒性较低。这些化合物既不是皮肤刺激物也不是皮肤致敏剂，吸入毒性和皮肤毒性都相当低。在大鼠、小鼠和/或兔子中既不致畸，对各种细菌菌株也不致突变。给大鼠亚急性和慢性投喂较高剂量的这些化合物总会导致肝脏出现一些组织病理学变化；然而，这些变化既不表明也不暗示具有致癌性。根据现有的毒理学信息，目前推荐的使用模式可能为人群提供足够的安全边际。然而，在将其应用扩展到农业害虫防治时，应从化学和生物学方面进行更广泛的研究，因为关于这些拟除虫菊酯在环境中的归宿信息很少。此外，其中几种化合物可能对某些鱼类和节肢动物具有很高的毒性。
